1. Field of the Invention
The present invention relates to a camera capable of switching from one of a plurality of picture formats to another so that pictures of various formats can be taken.
2. Related Art Statement
There have been various proposals for cameras enabling pictures to be taken by using Japanese Industrial Standards (JIS) 135 films in such a manner that the picture format of an image surface can be switched between a normal format (24 mm.times.36 mm) and a panoramic format (e.g., 13 mm.times.36 mm). The present applicant has also proposed, in Japanese Patent Application No. 3-155, a mechanism for switching the picture format between the normal format and a panoramic format. This mechanism includes a mask provided between the aperture of the camera body and the photographic lens. The mask is driven by a ring connected to an operating member to effect switching between the normal format and a panoramic format.
With the art shown in Japanese Patent Application No. 3-155, since the mask is provided between the aperture of the camera body and the photographic lens, when the lens barrel is collapsed, the photographic lens, etc. cannot be positioned in the vicinity of the aperture of the camera body. Thus, the overall camera is bulky, Moreover, the degree of freedom of design cannot be said to be excellent.
With the above art, since the distance between the light-sensitive surface of the film and the mask is relatively great, the boundaries between light-exposed portions and non-light-exposed portions of the film may not be sharp enough for some users. When the above art is applied to a focal-length adjustable camera, since the angle of incidence on the film surface may vary in accordance with changes in the focal length, a picture taken with a panoramic format may have a vertical dimension varying in accordance with the focal length.